1. Field of the Invention
The present invention relates to a face authentication technique.
2. Description of the Background Art
In recent years, various electronized services are being spread with development in the network techniques and the like, and the non-face-to-face personal authentication techniques are in increasing demand. To address the demand, the biometric authentication techniques for automatically identifying a person on the basis of biometric features of the person are being actively studied. The face authentication technique as one of the biometric authentication techniques is a non-face-to-face authentication method and is expected to be applied to various fields of security with a monitor camera, an image database using faces as keys, and the like.
At present, as an authentication method using two face images, a method is proposed, in which the face orientations in two images are set to be the same by using a standard stereoscopic model of a face, and luminance information of a predetermined region in the faces in the same orientation is obtained from the two images, respectively, and is compared, thereby collating the two images (refer to Japanese Patent Laid-Open No. 2004-288222).
The method, however, has a problem such that since the obtained face images are used as they are for authentication without evaluating the reliability, the recognition accuracy is not sufficiently high.